This invention relates to hand adjustable lever mechanisms. In one aspect, the invention relates to an adjustable hand lever mechanism comprising a nonmetallic handle in combination with a metallic coupling element, while in another aspect, the invention relates to a metallic coupling element of a nonannular design. In yet another aspect, the invention relates to a metallic coupling element with a trapezoidal configuration.
Adjustable hand lever mechanisms and similar items are well-known in the clamping and fastener art. These devices are used in applications in which frequent, multiple adjustments and/or clampings are required, e.g. on various industrial equipment, where tools are not practical due to space restrictions. Typically, these mechanisms attach to a spindle, shaft or similar device. As such, the adjustable hand lever mechanism must be able to rotatably engage and disengage the spindle, etc. and it usually accomplishes this through the action of a fastening element.
Various hand lever mechanisms are described by Kipp in U.S. Pat. No. 4,598,614 which is incorporated herein by reference. The mechanisms of most interest to Kipp are those comprising a nonmetallic hand lever and a metallic coupling element. As explained by Kipp, cost and weight consideration favor a nonmetallic, preferably a plastic, hand lever mechanism, but torque considerations favor a metallic coupling element since this element almost always engages a metallic fastening element.
As further described by Kipp, if the hand lever mechanism is to be useful for its intended purpose, then the metallic coupling agent must be incorporated into the nonmetallic hand lever in such a manner that one does not rotate with respect to the other during the operation of the hand lever mechanism. Kipp addressed this concern by designing his coupling element to have an annular configuration equipped with anchoring elements, e.g. projecting elements arranged uniformly along the outer periphery of the coupling element. These anchoring elements are embedded in the hand lever and as such, resist rotation of one about the other during the operation of the hand lever mechanism. While this design is generally effective for its intended purpose, alternative coupling designs are desirable for a number of reasons, including cost of manufacture, ease of assembly, operational effectiveness, and the like. Of particular interest are coupling element designs that do not include lugs, projections or similar protruding parts, either on the coupling element periphery or elsewhere on the element.